The term ombré may be used to describe a visual effect by which a color is graduated from dark at one portion, such as the bottom or side, of a surface or material to progressively lighter at another portion, such as the top or center, of a surface or material. The actual graduation may be from a darker color to a lighter color or shade, or to any combination of colors or shades. For example, an ombré effect may be formed in a textile by selectively dyeing the material. Similarly, through the careful selection of yarns and particular knitting patterns, ombré effects may be produced in fabrics using pre-colored threads. Ombré effects have also been applied to blended thermoplastic polymers through the selective extrusion of plastics having different colors, which may be used for decorative purposes. However, while ombré effects have been used on textile threadings and extruded plastics, they have not been adapted for use in connection with stain finishes. Stain finished may be applied to any material adapted for receiving stain and may be used in connection with large surfaces or surfaces having irregular patters or shapes.
The term “Material” as used herein means any material adapted for receiving stain, and may include, by way of nonlimiting example, fibrous materials derived from wood, solid woods, hardwoods, veneers, particle board, plywood, medium-density fiberboard, polymers, resins, and plastics. A veneer may comprise thin slices of wood, usually thinner than about 3 mm (⅛ inch), that are obtained by slicing large rectangular blocks of hardwood known as flitches. Veneer may be raw, having no backing material, or may be backed by a binding substrate such as paper. Additionally, multiple veneers may be laid up, or joined together to form larger pieces. Veneers may be laid up in various patterns such as, by way of nonlimiting example, book matched, i.e., where veneers are opened from the flitch much like pages from a book, slip matched, i.e., where veneers are joined together in the order they come from the flitch, radial matched, i.e., where veneers are cut into wedge shaped pieces and joined together, and diamond matched, i.e., where veneers are patterned to form various patterns. Veneers may be derived from any type of wood including, by way of nonlimiting example, cherry, maple, French ash, sycamore, birdseye maple, oak, ribbon stripe mahogany, wenge, and walnut.
Materials may be treated in a variety of ways, such as by way of staining Before applying stain to a material, the material may first be prepared to receive stain through bleaching. A bleach is a chemical that removes or lightens colors, often via oxidation. Common chemical bleaches may include, by way of nonlimiting example, chlorine bleach, a solution of about 3-6% sodium hypochlorite (NaClO), and oxygen bleach, which contains hydrogen peroxide or a peroxide-releasing compound such as sodium perborate, sodium percarbonate, sodium persulfate, tetrasodium pyrophosphate, or urea peroxide together with catalysts and activators, e.g., tetraacetylethylenediamine and/or sodium nonanoyloxybenzenesulfonate. Two-part oxygen bleaches may be used in the whitening of, for example, wood materials. The bleaching time of a material may be decreased by exposure to direct sunlight.
A wood stain may comprise a colorant suspended or dissolved in solvent. The solvent may be, by way of nonlimiting example, water, alcohol, or petroleum distillate. Two types of colorants may be used, namely, pigments and dyes. Dyes may be microscopic crystals that dissolve in solution, while pigments may be much larger particles that remain suspended in solution. Fine-grained woods, such as cherry or maple, may be colored by dyes, but pigments may be too large to attach to the small pores of such woods. Some wood stains may contain binding agents which allow pigments to bind to even fine-grained woods. Typically, pigments will not give much color to fine-grained woods, but will deeply color woods with large pores, such as, for example, oak. Most commercial wood stains contain both dye and pigment and the degree to which they stain wood is mostly dependant on the length of time they are left on the wood.
Varnish may be a transparent, hard, protective finish or film and may be used to seal the surface of a material. Varnish may be a combination of a drying oil, a resin, and a thinner or solvent. While varnish may be glossy in appearance, it may also be designed to produce satin or semi-gloss sheens by the addition of flatting agents. Varnish may have little or no color, be transparent, and have no added pigment. After application, the film-forming substances in varnish either may harden directly, as soon as the solvent has fully evaporated, or may harden after evaporation of the solvent through certain curing processes, primarily chemical reactions between oils and oxygen from the air and chemical reactions between components of the varnish.
For example, resin varnishes may dry by evaporation of the solvent and may harden almost immediately upon drying, while acrylic and waterborne varnishes may dry upon evaporation of the solvent but may experience an extended curing period. Oil, polyurethane, and epoxy varnishes may remain liquid even after evaporation of the solvent but quickly begin to cure, undergoing successive stages from liquid, to “sticky,” to “dry to the touch,” to hard. Environmental factors such as heat and humidity may play a large role in the drying and curing times of varnishes. The drying and curing time of all varnishes may be decreased by exposure to an energy source such as sunlight, ultraviolet light, or heat.
A lacquer may be a quick-drying, solvent-based varnish, which may include a thinning agent such as, by way of nonlimiting example, butyl acetate, xylene or toluene. Examples of lacquer may include, for purposes of illustration, nitrocellulose lacquers, acrylic lacquers, and water-based lacquers.
Materials may also be treated by sanding the material to make the surface uniform. Sanding may occur by hand or through use of a mechanized sander, such as an orbital or vibrating sander. Sandpaper may be a form of paper where an abrasive material has been fixed to the surface of the paper. Sandpaper may be used to remove material from surfaces, either to make the surface smoother, to remove a layer of material, or sometimes to make the surface rougher. Grit size refers to the size of the particles of abrading materials embedded in the sandpaper. A number of different standards have been developed for grit sizes, which establish the average grit size and the allowable variation from the average. The two most common are the United States CAMI (Coated Abrasive Manufacturers Institute) and the European FEPA (Federation of European Producers of Abrasives) “P” grade, which is identical to the ISO 6344 standard.